US1902780A - Knitted lining for rubber footwear and method of making same - Google Patents

Description

R. M. HOLDEN ET AL March 21, 1933.

KNITTED LINING FOR RUBBER FOOTWEAR AND METHOD OF MAKING SAME A M A Al Filed April 11, 1930 mar m rMHJZde/Z f i z md-erfr Patented Mar. 21, 1933 UNITED STATES PATENT- E Rdenn M. HOLDEN ND JOHN F. ROBERTS, or wononsrna. MASSACHUSETTS, A's} SIGNORS To HOLDEN KNITTING 00.01 WORCESTER, MASSACHUSETTS, ACORIEORA f TIN on MAssAcHUs TTs' KNITTED LINING FOR RUBBER FOOTWEAR AND ivrnTiaon or MAKING SAME 7 Application filed A ril 11,

The present invention relates to a knitted linin for rubber foot wear such as bo0ts,and

the li e, and an improved method of produc-z ing such linings. The lining is particularly adapted .for use in the manufactureof rubber articles of foot wear that are formed, or

ess.v As aresult of the close fit obtained be-' tween the last and our improved lining, the

lining itself becomes uniformly incorporated in the cured rubber of the finished article and so presents a smooth inside surfacelto the 2 foot of the wearer free ofwrinkles. In addi-' tion, our lining is somade that the only seam therein becomes firmly embedded in the sole of the article of footwear the seam being formed at a'place where it is not noticeable 2 to the wearer. .The above and other advantageous features of our invention will hereinafter more fully appear, reference being had to the accompanying drawing in which Fig.1 is a plan View of a length of tubular knitted material fromwhi chthe lining is to be made. i

Fig. 2 is a view in side elevation of a completed lining produced in accordance with our invention.

F ig. 2a is a fragmentaryrplan View of the lining foot. 7 V y y Fig. 3 is a view in side elevation of a boot last or tree on which the lining of Fig.2'is to 40 be drawn. i p

Fig. 4: shows the llning on the last;

Fig. 5.is a transverse sectional view of a completed boot incorporating the lining of Fig. 2 and showing the location of the toe seam. o i

Fig. 6 is a side View of a lining similar to the lining shown in Fig. 2, but knitted in a different way.

Fig. 7 is a fragmentary view showing a further modification of the lining of Fig. 2.

v 1930.: Serial No. 443,358. I

Like reference characters refer to like parts in the different figures. y

In carrying outour invention, a length of material generally tubular in form, as shown in Fig.1, is produced by a circularknitting machine with a portion 1 knitted in plain rib stitch. That portionjofthematerial extending from the line 00-6 to the'line c-d is then knitted with a portion. 2 in plain rib; stitch, while the adjacent portion 3 is knitted with'a tuck stitch. In knitting the dissimilar portions 2 and 3, successive continuous courses are knitted partially in plain rib stitch and partially in tuckstitch, and as the portions 2 and 3 emerge from the machine,

the falbric takes the form of an arc'between,

thelines aZ and 0d with the porti0n'2 of larger radius because of the fact that the tuck stitch portion 3 contains a smaller number of stitches than there are'in the ribstitch portion' 2 for a given number of courses, with r each tuck stitch containing more yarn than a rib stitch. The gathering together of the stitches of the portion Sincident to'tuck as compared to the line w0.

stitching results in sl 1orteningthe line b d -A further portion 4 of, the fabric,'extending from the line 0'cZ to theend of the tube is then knitted withtuck. stitch courses similar to the portion 3, and owing to'the loose ness of this portion 4, as compared to the por-.

tion 1 of plain rib stitch, the portion ,4 is of considerably greater diameter than the por-' tion 1. As a result of the above described manner of knitting, a, length of tubular fabric is produced with a straight portion of substantially uniform diameter, an arcuate portion of slightly increasing diameter and a relatively long andfslightly tapered portion of still greater diameter. v V

' The next step, in carrying out our inven- Y tion resides in bringing the edges of the portion 1 together and then cutting and sewing 7 the'edges, to provide a curved seam 5 whichextends transverselyto the axis of thetubular portion 1, as shown in Fig. 2a, the seam 5 lying in a plane at right-angles to the plane in a i which the lining is curved when lying flat. Bycomparing the completed lining of Fig.2 with the boot last of Fig. 3, is apparent inverted for this purpose,no particular skill is required on the part of the operator, since the curved portion or" the lining naturally points towards the toe of the last; consequently the seam 5 always comes at the proper position with its stitches facing outward from the flat sole of the last.

' After the lining has been drawn onthe last, as shown in Fig. I, the different parts of un-,

cured rubber ofwhich the boot is composed are built upon the lining covered last in a manner well known to those skilled in the art. These rubber boot par-ts include a sole which is placed fiat on the covered last in en-- gagement. with'the toe seam stitches 5 and'is held in position by suitable leg and vamp pieces. The boot is then completed by subjectingthe'rubber partsto a vulcanizing process, with or without pressure as desired,

35. than the remainder of the boot. As a result which results in the lining becomingan integral part of the completed artlcle. In the completed boot shown in section in Fig. 5 it,

should be noted that'the toe stitching 5 is firmly embedded in the sole 6 of the boot which is of considerably greater thickness of the close fitof the lining on the last and the embedding of the seam in the rubber sole,'the lining presents a smooth unbroken inside surface throughoutwith no wrinkles or seams noticeable to the foot of the wearer, and with no weak spots in the rubber due to irregularities in the thickness of the lining.

Another advantage of our, lining resides in the fact- ,that since the rib stitching of the toe, sole andheel portions of the lining is closer in texture than the instep and leg tuck stitching, these denser portions of the lining are better able to withstand the greater wear to which they/are subjected, as compared to the instep and leg portions. The wearing qualities of the lining in this respect can be further increased by introducing extrathreads into those courses of the lining between the lines a-b and 0d which are knitted partially in rib stitch and partially in tuck stitch, the extra threads being introduced either into the rib stitched portion 2, or into both portions 2 and 3. A portion of'a lining knitted in this manner is shown in Fig. 7, wherein the presence of the extra material is indicated in the rib knit portion 20. by the closer spacing of the wales.

-Referring now to Fig. 6, there is shown a modified form of lining which is adaptedto be made on an ordinary hosiery machine wlth a single stitch, whereas the lining shown in Fig. 2 is made on a cylinder and dial machine. In knitting this modified form of lining, a toe portion 7 is knitted with: a relatively short stitch using small thread, after which a portion 8 is knittedwith' stitches of diiferent length, the stitches 8w being shorter,

than the stitches 8b andthe stitches 86 being knitted with larger thread as compared to.

the thread used for knitting the'portions 7 and 8a. After this, athird portion 9 is kniti' ted with stitches longer than the stitches of the other portions and with thread larger than the thread used in either the portions 7 or 8. As a result ofthe above described manner of dissimilar stitchingwithdiiferent sizes of yarn, the intermediate portion 8 of the completed lining assumes a somewhat arcuate' form with one side longerthanthe other so that'it will fit closely over thelast shown in Fig. 3. The lining shown in Fig.6 also provicles a toe seamlO disposed in the same manner as the toe seam 5 ofthe lining shown in Fig. 2'and this particular typeof lining is claimed in our copendinpdivisional appli- V cation Ser. No. 657,286, filed Feb. 17, 1933. l I

of molded rubber foot wear. In the manufacture of molded foot wear, it'is customary to'employ a last having'walls of yieldable material, such as a combination'of rubber and fabrlc, thls mater al being of such stifiness as to maintain its shape against thev forces in- V volvedin building the boot thereon. At the sametime, a last of this type possesses s'uiii.

cient elasticity to be expanded by'fluid pres- I sure to press the boot material against the rig id walls of an inclosing mold. We have found that a lining knitted in themanner shown in Fig. 2 possesses sufiicient elasticity to expand uniformly with the last when the latter is inflated by pressure during the vulcanizing op? eration. Furthermore, the pressure exerted bythe expanded last outwardlyagainst the rigid walls of the inclosing mold serves to ac-.

tually embed the longitudinal ribs ofthelining in the rubber inclosing the lining, there-- by giving a maximum degree of adhesion between the rubber'and the lining. in the completed boot.

On the other hand, the type of lining shown in Fig. 6 is particularly adapted for the manufacture of rubber foot wear on a rigid last, since the relatively tighter single stitching of the lining shown in Fig. 6 is adapted to fit more closely to the'last and does not possess the elasticity of the lining. shownin Fig. 2.

In the manufacture of rubber footwear with a rigid last, it is customary to exhaust the air from the inside ofthe last during the vulcanizingoperation which. results in a difference 1,9o2,7so i Y 3 of pressure between the outside surface of the" rib and partially in tuck stitch, with the rib our invention we have provided animproved built up rubber boot parts surrounding the stitching having the greaterradius, and a leg lining and the surface of the'last. This difportion knitted in tuck stitch.

ference in pressure results in the rubber and the lining being pressed against the unyielding surface of the last so that the last determines the form of the completed article. For this reason, the lining of Fig. 6, with its rela tively slight elasticity and its absence of pronounced longitudinal ribs on the side in contact with 'the'rubber is better suited for 7 this mode of manufacture than the lining shown in Fig. 2, sincethis lining will adhere uniformly to the rubber without exhibiting any tendency for the stitching of the lining to affect the appearance of the outer rubber surface of the finished article of foot wear.

From the foregoing it is apparent that by knitted lining and a method of making the same by the practice of which it is possible. to produce linings that are particularly adapted for use in connection with the manufacture of formed rubber foot wear, such as boots and overshoes, our linings, when incorporated in such articles, presenting a smooth unbroken surface which possesses considerable warmth for the foot of the wearer.

We claim: a

1. The improvement in the manufacture of a lining for a formed rubber article which consists in knitting a length of tube with one portion in rib stitch, another portion partially in rib and partially in tuck stitch and a third portion in tuck stitch, the mixed rib V V and tuck stitched portionlying between the other portions'to impart an arcuate form to the lining.

2. The improvement in the manufacture of a lining for a formed rubber article which consists in knitting a length of tube with one portion in rib stitch, another portion partially in rib and partially in tuck stitch and a third portion in tuck stitch, with the mixed rib and tuck stitched portion lying between the other portions and then closing-the rib stitch portion by a curved seam extending transversely across the'tube, with said seam lying in a plane at right angles to the plane in which the mixed stitch portion is curved.

3. A one-piece fabric lining for formed rubber articles of footwear knitted in tubular form with one side longer than the other, with the stitches at its end portions of different character, and with the stitches of an intermediate portion of mixed character corre- I sponding to the stitches of said end portions.

4:. A- one-piece fabric lining for, formed rubber articles of footwear knitted in tubular form to assume a shape closely approximating the shape of the last on which the article is formed,-said lining comprising a foot portion knitted in rib stitch, a curved instep and heel portion knitted partially in ROGER M. HOLDEN.

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